The CSIRO says energy generated from wave power could be a major contributor to Australia’s energy needs. But wave generation capacity worldwide is miniscule. It is a new area and power generation equipment is still being designed and tested in the search for maximum efficiency. Matthew Crawford visits the Australian Maritime College in Launceston where an oscillating water column device is being tested.

Transcript

Robyn Williams: And for more on energy research and wave power we return to Tasmania with Matthew Crawford.

Neil Bose: Over the years there have been a lot of wave power devices that different inventors have come up with. Quite a lot of them have got to demonstration stage. Relatively few are actually on the grid producing power continuously. The oscillating water column device, of which this is an example, has been shown really to be one of the ones that does seem to last the course.

Matthew Crawford: And this is Professor Neil Bose at the University of Tasmania's Australian Maritime College. In Launceston we're standing on a gantry over the college's 100-metre-long towing tank. This is the largest facility of its type in Australia, and it has been used to test over 500 models of ships, submarines, oil rigs and all sorts. Today they have suspended beneath us a clear plastic chamber about a metre high and with the lower portion submerged in the water, and this is a model for what's going to be a pilot wave energy installation four kilometres off Port MacDonnell in South Australia. If the pilot project works out, this type of device, this oscillating water column, could be a model for installations on other parts of Australia's coast.

Neil Bose: What happens is that the wave goes up and down inside the chamber, the orifice where the turbine is is relatively small, relative to the surface area of the wave, and you get a puff of air going out and coming back in. And the turbine rotates the same way, no matter which way the wind is coming through the orifice, and the electrical power generator is connected to the turbine.

Matthew Crawford: So what we've got is a tall chamber sitting upright in the water. At the bottom a large scoop points into the waves. At the top there is only a small outlet, so the incoming water pushes air up the chamber which is then drawn back down as the water falls, and it's that breathing in and out at the top which spins the turbine and generates the electricity, as Neil just described. And that's also where we get the term 'oscillating water column'. There's one of these devices working off Pico Island in the Azores, and a number of totally different wave energy concepts in development elsewhere.

Neil Bose: If you look back 30 years to when wind power developed, there were a lot of devices, and now when you look at the devices that are mainly in use, you see the horizontal axis wind turbines, that's what people imagine as the classic wind turbine. But in the early '80s there were a whole load of different devices. And so it is the same with wave power. There are a whole load of different devices, it has not yet been proven which one has got the market lead. So we're going from research into development into the first really commercial designs, but those still haven't made an impact on the market yet. When we come to develop and put out, say, tens of these across the coast to extract wave energy, then you will start to see the successful designs.

Matthew Crawford: And the Australian government has identified wave energy, along with geothermal energy, as a relatively untapped resource, but one that holds enormous potential. The CSIRO predicts that just 10% of the wave energy coming in along the southern coast could provide up to half of the country's energy needs. The work here brings together the Maritime College and the renewable energy company Oceanlinx and was made possible by a linkage project grant from the Australian Research Council. It's the geometry of this device that is being tested today. Alan Fleming is one of the researchers here, and he's been using a laser to help work out the ideal shape.

Alan Fleming: The geometry interacts with the water flow, and so it's very important with the way the device reacts with the incoming waves and how that's converted. So it has a big impact on the conversion efficiencies. With the laser we illuminated a light sheet inside the device. We were able to highlight particles and capture that with a specialised camera. And so with that we were able to attract the water particle motions inside the device. We're still at the early stages of our testing, but we're working on some new geometry designs which we're planning to test in the next couple of months. So we've got two different geometries that we're looking at doing, based on the results of the previous work.

Neil Bose: Efficiency is important because the cost of the device is tied in eventually to the cost of power that is delivered to the customer. So you want to extract as much energy from the waves for as little expense as possible. So that's why efficiency is important. Going ahead, what we see is more of these devices forming part of the energy supply for a given state or a given country. You wouldn't expect all the energy to be produced from wave power, but when you combine wave power with coal and other devices such as wind turbines you have a very diversified, very reliable system overall. We've got several different tests going on, this is one of them. For the Australian Maritime College, ocean renewable energy is a very important research area for us over the next few years.

Matthew Crawford: In Launceston for The Science Show, Matthew Crawford.

Robyn Williams: Thanks Matthew. Next week, maths, the mathematics of risk, from Professor David Spiegelhalter in Cambridge, on a return visit to The Science Show. And Simon Pampena, who is a maths ambassador, if you will.

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Comments (1)

I Ortiz :

25 Oct 2012 4:19:33am

The Automatic Pitch Turbine can be used to develop power from an OCW or Oscillating Column of Water system. The Automatic Pitch Turbine is more efficient than the Well's Turbine because it has an attack angle of 45 degrees in both direction of the air flow. The Automatic Pitch Turbine's pitch is automatically adjusted to the correct angle by the direction of the air flow. The speed of the turbine is controlled by the Sea Wave Turbine Speed Control that runs parallel to the Automatic Pitch Turbine.US 8,193,653 B2 Automatic Pitch Turbine.